"Chemical computer" key to future technology?
June 11, 1998 08:22 PM
By Michael Kahn
WASHINGTON, June 11 (Reuters) - A supercomputer using factory-reject chips and
having more than 220,000 defects, each deadly enough to disable any other
machine, could be the forerunner of "chemical computers" that are faster,
cheaper and more powerful, researchers said on Thursday.
The Teramac computer could offer engineers a way to build computers chemically
-- something necessary for innovation in the field to continue, they said in a
report published in the journal Science.
"This is another path to hopefully continue the computer revolution," said
Philip Kuekes, a computer architect at Hewlett-Packard Laboratories HWP in
California, who helped build Teramac.
Teramac's defect tolerance made the researchers realize they could
theoretically build smaller computers using chemistry.
"Chemistry allows you to build very small things on an atomic scale even if
they aren't perfect," Kuekes said in a telephone interview. "We believe we can
build smaller-sized computer circuits using chemical reactions."
He explained current silicon technology, which uses light to produce chips,
has
limitations. When wavelengths become too short they turn into X-rays and
damage
molecules, Kuekes said.
"We can't keep going in that direction because we will eventually destroy what
we are trying to build," he said.
But making components chemically allows computer builders to shrink the
size of
circuits. This means faster machines, Kuekes said.
"The signals don't have as far to go and are much faster," Kuekes said.
Teramac, for example, has more connections than normal computers and for
certain applications was 100 times faster than Hewlett-Packard's top
workstation, Kuekes pointed out.
The computer was able to disregard the flaws because its makers set up the
wires and connections in a way similar to a series of city streets with no
dead
ends. This let Teramac route around defects by choosing a different pathway,
Kuekes said.
"The computer solution found a solution that avoided the defect and worked
around them," Kuekes said.
Using chemistry to make defect-tolerant computers will also help lower the
skyrocketing costs it takes to manufacture the chips needed to run computers,
the researchers said.
"Today computer (chips) have to be perfect. The significance is it will drop
the cost if they don't have to be," Kuekes said.
A large part of the expense in manufacturing microprocessors today is the
multibillion-dollar plants, where the cost of making perfect devices requires
increasing cleanliness and precision, he added.
But with defect-tolerant computers these plants are unnecessary because the
chips need not be perfect.
"As perfect devices become more expensive to fabricate, defect-tolerance
becomes a more valuable method to deal with imperfections," the authors
wrote.
Jim Heath, a chemist at the University of California Los Angeles, said
building
a computer chemically lets researchers design computers that exceed the
limitations of silicon-chip technology.
"Theoretically computers can be much more efficient ... but you're not
going to
do it with silicon technology," said Heath, who worked on the study.
While, actually constructing a computer in a chemical lab is at least 10 years
away Teramac shows it is now feasible, Heath said in a telephone interview.
"It suddenly gives people in the field a goal," he said. REUTERS